Bubble caps for bubble columns

ABSTRACT

Bubble cap tray for bubble cap columns, comprising a plurality of bubble caps, each bubble cap having a top and a skirt extending downwardly from the top, openings for discharge of gas through the bubble cap at spaced intervals along the skirt, dividing the skirt into gas discharge openings and closed areas intermediate with the gas discharge openings, the openings of each cap confronting closed areas of the adjacent caps, so that gas streams issuing from the cap openings are not directed against one another.

United States Patent Kloss 1 Sept. 26, 1972 [54] BUBBLE CAPS FOR BUBBLE3,055,646 9/1962 Eld et al. ..261/1 14 VT COLUMNS 3,287,004 11/1966Nutter ..26l/l l4 VT Inventor: H J Kloss, Hilde, Braun et a] manyFOREIGN PATENTS OR APPLICATIONS [73] Assrgnee: Julius Montz Gmbll,l-lilden, Ger- 645,354 7/1962 Canada many [22] Filed: April 2, 1970Primary Examiner-Tim R. Miles Assistant Examiner--Steven H. Markowitz[21] Appl' 29347 Attorney-Burgess, Dinklage & Sprung [30] ForeignApplication Priority Data [57] ABSTRACT APril 5, 1969 l' 19 17 536-1Bubble cap tray for bubble cap columns, comprising a plurality of bubblecaps, each bubble cap having a top UOSO e A, and 3V downwardly from top[51] Int. Cl. ..B0ld 3/20 openings for discharge f gas through h bubblecap [58] new of Search "261/113, 114 114 114 at spaced intervals alongthe skirt, dividing the skirt 261/1 14 J D into gas discharge openingsand closed areas intermediate with the gas discharge openings, theopenings {56] References Cited of each cap confronting closed areas ofthe adjacent UNITED STATES PATENTS caps, so that gas streams issuingfrom the cap openings are not directed against one another. 2,225,39012/1940 Ostergaard ..26l/l 14 R 12 Claims, 11 Drawing FiguresPATENTEDSEPZG m2 SHEEI 1 OF 4 Inventor:

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1 BUBBLE CAPS FOR BUBBLE COLUMNS BACKGROUND OF THE INVENTION Theinvention relates to a bubble tray for bubbletype exchange columns. Witha bubble tray, a downwardly open pot, which is a so-called bubble cap,is disposed above an opening in the tray plate, the rim of said capbeing spaced from the tray plate by an amount which is smaller than theheight of the liquid on the said plate. As a consequence, the gasesflowing upwardly through the opening first of all ascend into theinterior of the cap and from thence downwardly around the rim of thecap, so that they are compelled to flow through the liquid over apredetermined distance. Whereas the caps in-many bubble trays are ofcircular cross-section, the term bubble cap is used herein is also to beunderstood to cover trays with which the caps have different forms, forexample, the form of elongated rectangles.

Hitherto, with such icaps, the gases were led out over practically theentire periphery of the rim of the caps, while with elongated caps, theywere led out over the entire length of the two longitudinal sides, fromthe cap.

The invention has for its object to increase the efficiency of suchtrays. If an attempt is made to increase the efficiency of such trays byproviding more caps, that is to say, having the caps more denselyarranged, it is found that the gases between the caps project the liquidupwardly. The result is a throughflow of different strengths atdifferent parts of the liquid. Consequently, the possibility ofimproving the efficiency by increasing the number of caps is greatlylimited, especially with high gas flows.

According to the invention, this difficulty is avoided by the cap havingpassage openings for discharging gas only on parts of its periphery, andby the caps of the tray being so arranged that no opening of a cap isfaceto-face with an opening of an adjacent cap. Thus if any openings ofa cap are oriented directly towards an adjacent cap, the parts of theadjacent cap opposite such openings are imperforate.

The horizontal cross-section of the caps can assume different forms; byway of example, it may have the form of a circle or of a uniform,even-numbered polygon, the form of a rectangle with substantially equalside lengths or with very different side lengths. Using a cap of whichthe cross-sectional form is an elongated rectangle, it is eitherpossible for alternately closed and open parts to be disposed adjacentone another on the longitudinal sides, or it is also possible for theentire longitudinal side to be open, while the transverse sides areclosed. In such a case, it is expedient for such caps to be so arrangedthat several rows of such caps disposed in series in the longitudinaldirections and with spacings equal to their length are situated at rightangles to one another, that caps are alternately disposed at rightangles to one another in each of these directions and the liquid streamsleaving the longitudinal sides of the similarly directed caps ofadjacent rows are offset from one another.

The caps can be fixed on the tray above a passage opening for the gas.However, they can also be let into corresponding openings of the trayand thus close off .the openings, if they are not lofted by the pressureof the upwardly flowing gas. They then operate as valves. In such'cases,it is desirable for the caps to be made of sheet metal with projectionsor stops, which limit the upward and downward movements of the cap inrelation to the tray.

Several embodiments of the invention are shown by way of example in thedrawings.

FIG. 1 is a plan view of a bubble tray with a large number of caps,which are shown in horizontal section.

FIG. 2 is a perspective view of a cap which corresponds to the capsshown in FIG. 1.

FIG. 3 is a perspective view of another form of cap for such a bubbletray.

FIG. 4 is a view, partly in section and partly in perspective, of abubble tray with caps having a cross-section which is in the form of arectangle of substantially equal side lengths.

FIG. 5 is a perspective view of a cap of hexagonal cross-section.

FIG. 6 is a cap of a similar type to FIG. 5, but which is not fixed onthe bubble tray, but is let into said tray.

FIG. 7 is a plan view of a bubble tray having three caps of rectangularcross-section, the longitudinal sides of said caps being considerablylonger than the transverse sides.

FIG. 8 shows a part of the bubble tray in FIG. 7, partly in section andpartly in perspective.

FIG. 9 is a plan view -of a bubble tray somewhat similar to FIG. 7.

FIG. 10 is a view, partly in section and partly in perspective, showinganother form of bubble tray according to the invention and having capsfixed on the tray.

FIG. 11 is also a view, partly in section and partly in perspective, ofa bubble tray similar to FIG. 10, but in which the caps are let intocorresponding openings of the tray.

The horizontal tray 2 which is shown in is fixed to the column wall 1and limited by the two weirs 3 and 4 which are parallel to one another.The weir 4 separates a section 5 of the plate from the column tray saidsection lying in the same plane as the column tray 2. The space 6between the weir 3 and the column tray 1 is empty. The liquid flowin gover the weir 3 flows through the space 6 on to the tray section 5 ofthe subjacent tray, which is thus oriented in the other direction fromFIG. 1, i.e. turned through 180. The tray section 5 likewise receivesthe liquid to be treated from the tray section situated above it, thesaid liquid their being steadied over the weir 4 and flowing on to thetray 2. The height of the liquid which is on the tray 2 is thusestablished by the height of the weir 3. The tray 2 has a number ofround openings 7, each of which is covered by a cap 8. As shown in FIG.2, the cap 8 has the form of a cylindrical, downwardly open pot with atop 8a and lateral cut-outs 80, which are distributed uniformly aroundthe circumference, and each have a length equivalent to 60. These caps 8are so arranged on the base 2 that always an opening is disposedopposite a closed part 8b of the adjacent cap in the radial direction.The axial height of the cut-outs 8c is somewhat smaller than the heightof the weir 3, so that the liquid level is somewhat higher than theupper boundary of the cut-outs 8c.

Gases flow upwardly through the openings 7 of the tray 2 (the term gasesis used here in the most general sense and covers more especially alsovapors). Consequently, they penetrate through the liquid disposed insidethe caps and force the liquid out of the openings 80, as shown by thearrows in FIG. 1. The streams of gas thus discharging from the openings8c-encounter the closed surfaces 8b of the adjacent caps and are in anycase not directed towards one another in such a way that the liquidcould be agitated by them. Consequently, it is possible for the caps tobe arranged in comparatively dense formation and thus to provide acomparatively large number of caps onone bubble tray.

The cap according to FIG. 3 differs from the cap according to FIG. 2 bythe fact that several openings 8d are provided instead of the cut-out8c, said openings not extending as far as the base; a group of theseopenings 8d is disposed in a region equivalent to about 60 of thecircumference of the cap, so that closed wall surfaces 8b remain betweentwo such groups of openings 8d.

The caps according to FIG. 4 have a substantially square cross-section.The height thereof is smaller than the height of the liquid which is onthe tray 2. Each of these caps consists of a sheet bent to trapezoidalform, the upper side thereof being horizontal, i.e. parallel to the tray2. The plates 9 are fixed on the tray 2, and in fact in each case abovea gas passage opening 7. These caps 9 thus have two openings 90 whichare opposite one another= and two sloping walls 9b which are likewiseopposite one another. The caps are arranged in parallel rows, and alwaysin such a way that the opening 90 of one cap faces the closed wall 9b ofthe adjacent cap.

FIG. 5 shows a cap of hexagonal cross-section which is connected to thetray and in which alternate side surfaces 10b are closed and 100' areopen.

FIG. 6 shows a cap which only differs from the cap according to FIG. 5by the fact that its upper side 10a is extended by projections 10d, andthat its side walls 10b are extended by horizontal projections 10e. Thiscap is so fitted into a corresponding hexagonal opening 7 in the traythat the projections 10e are disposed beneath the tray and theprojections 10d above the tray. This cap is lifted by the pressure ofthe ascending gased, the projections 10d and 10e limiting the upwardmovement of the cap.

The tray 2 which is shown in plan view in FIG. 7 has three openings 7which are parallel to one another and which are for the ascending gases.Each of these openings 7 is covered by a cap 11, which has in horizontalcross-section the form of a rectangle, having long sides the length ofwhich is substantially greater than that of the transverse sides 11f.The long sides consist alternately of closed areas 11d and open areas11c (see also FIG. 8). With each of the trays 11, an opening llc isdisposed opposite a closed area 11d. The three caps 11 are so arrangedthat the opening 110 of one cap is opposite a closed area 11d of. theother cap. The opening 7 in the tray 2 has been formed by correspondingflanges having been stamped out of the tray 2 and then bent upwardly ata right angle.

The tray according to FIG. 9 only differs from the tray according toFIGS. 7 and 8 by the fact that, as regards the individual caps 11, thelateral openings 11c face one another.

According to FIG. 10, caps 12 of rectangular crosssection are soarranged in rows parallel to one another that the caps 12 lying oneafter the other in one row are disposed at a distance a from one anotherwhich is just as large as their length l. The spacing b between thecenter lines of two rows of caps 12 is also equal to the length l.Arranged at regular intervals at right angles to the rows of caps 12 arelike rows of identical caps 12', the arrangement being such that theirspacings a and b are equal to the spacings a and b. The caps 12 and 12are closed at their end faces 12b and 12b and are provided on theirlongitudinal sides and throughout their length with an opening 120 or120. In this way, large outlet openings 12c and 120 are provided,without the streams discharging therefrom being directed opposite oneanother.

The tray according to FIG. 11 differs from the tray according to FIG. 10by the fact that the caps 13 and 13 are let into the openings 7 of thetray 2 and are provided with projections 13d and 13e, which limit theirupward and downward movement in relation to the tray 2. In addition, theflanges 7a and 7b, which are stamped out from the tray 2 to form theslot 7, are bent over downwardly in such a way that they convergeupwardly.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

Iclaim:

1. Bubble tray for bubble cap columns, comprising a weir and a downcomerat opposite sides of the tray, a plurality of openings in said traybetween said weir and said downcomer, a plurality of closely spacedcaps, each cap covering one of said openings and having a top and askirt extending downwardly from the top, openings for discharge of gasthrough the bubble cap at spaced intervals along the skirt, dividing theskirt into gas discharge openings and closed areas intermediate with thegas discharge openings, the openings of each cap confronting closedareas of the adjacent caps, so that gas streams issuing from the capopenings are not directed against one another.

2. Bubble tray according to claim 1 having caps which in. horizontalcross-section are in the form of a circle or in the form of a hexagonwith alternately three sections having an opening or openings for thepassage of gas and three imperforate sections.

3. Bubble cap tray according to claim 1, wherein the horizontalcross-section of the caps is rectangular and not of substantiallydifferent side lengths, skirt openings extending downwardly from twoopposite sides and skirt closed areas extending downwardly from theother two sides.

4. Bubble tray according to claim 1, characterized in that thehorizontal cross-section of the caps has the form of a rectangle, thelength of which is considerably greater than the width and of which thelongitudinal sides are open to a substantially uniform extent throughouttheir length, while the transverse sides are closed, and in which anumber of such caps are so arranged at right angles to one another thatseveral rows of such caps disposed one after the other in thelongitudinal direction and at intervals equal to their length are sodisposed at right angles to one another that caps alternating in each ofthese directions lie at right angles to one another and the streams ofliquid discharging from the longitudinal sides of the caps in the samedirection in adjacent rows are offset from one another.

that the longitudinal openings of the tray beneath the caps are formedby stamping out two identical longitudinal flanges, which are so bentover downwardly that they converge upwardly.

6. Bubble tray for a bubble-type exchange column according to claim 1,said bubble tray having a number of openings for the passage of gas, anumber of bubble caps over the openings, each cap having a peripherywith openings therein leaving imperforate sections of the periphery, thecaps being so arranged that each cap has at least one opening facing animperforate section of an adjacent cap but no openings facing an openingof an adjacent cap.

7. Bubble tray according to claim 6, having caps which in horizontalcross-section have the form of a circle or a uniform even-numberedpolygon and alternately have open sections for the passage of gas andimperforate sections, the said sections being of approximately the samesize.

8. Bubble tray according to claim 6, having caps which in horizontalcrosssection have the form of an elongated rectangle, and, on the longsides thereof, open and closed sections of substantially equal lengthalternating with one another.

9. Bubble tray according to claim 6, having caps which in horizontalcross-section have the form of a rectangle with not substantiallydifferent side lengths, two opposite sides of the rectangle being openand the other two sides being closed.

10. Bubble tray according to claim 9, characterized in that the closedportion of the periphery of one cap which is facing an open peripheralportion of an adjacent cap rises obliquely upwards.

' ll. Bubble tray according to claim 6, characterized in that the capsare let into corresponding openings of the tray and thus close off theopenings if they are not lifted by the pressure of an upwardly flowinggas.

12. Bubble tray according to claim 11, characterized in that the capshave projections or stops on their upper and lower rims, which limittheir upward and downward movement relatively to the tray.

1. Bubble tray for bubble cap columns, comprising a weir and a downcomerat opposite sides of the tray, a plurality of openings in said traybetween said weir and said downcomer, a plurality of closely spacedcaps, each cap covering one of said openings and having a top and askirt extending downwardly from the top, openings for discharge of gasthrough the bubble cap at spaced intervals along the skirt, dividing theskirt into gas discharge openings and closed areas intermediate with thegas discharge openings, the openings of each cap confronting closedareas of the adjacent caps, so that gas streams issuing from the capopenings are not directed against one another.
 2. Bubble tray accordingto claim 1 having caps which in horizontal cross-section are in the formof a circle or in the form of a hexagon with alternately three sectionshaving an opening or openings for the passage of gas and threeimperforate sections.
 3. Bubble cap tray according to claim 1, whereinthe horizontal cross-section of the caps is rectangular and not ofsubstantially different side lengths, skirt openings extendingdownwardly from two opposite sides and skirt closed areas extendingdownwardly from the other two sides.
 4. Bubble tray according to claim1, characterized in that the horizontal cross-section of the caps hasthe form of a rectangle, the length of which is considerably greaterthan the width and of which the longitudinal sides are open to asubstantially uniform extent throughout their length, while thetransverse sides are closed, and in which a number of such caps are soarranged at right angles to one another that several rows of such capsdisposed one after the other in the longitudinal direction and atintervals equal to their length are so disposed at right angles to oneanother that caps alternating in each of these directions lie at rightangles to one another and the streams of liquid discharging from thelongitudinal sides of the caps in the same direction in adjacent rowsare offset from one another.
 5. Bubble tray according to claim 4,characterized in that the longitudinal openings of the tray beneath thecaps are formed by stamping out two identical longitudinal flanges,which are so bent over downwardly that they converge upwardly.
 6. Bubbletray for a bubble-type exchange column according to claim 1, said bubbletray having a number of openings for the passage of gas, a number ofbubble caps over the openings, each cap having a periphery with openingstherein leaving imperforate sections of the periphery, the caps being soarranged that each cap has at least one opening facing an imperforatesection of an adjacent cap but no openings facing an opening of anadjacent cap.
 7. Bubble tray according to claim 6, having caps which inhorizontal cross-section have the form of a circle or a uniformeven-numbered polygon and alternately have open sections for the passageof gas and imperforate sections, the said sections being ofapproximately the same size.
 8. Bubble tray according to claim 6, havingcaps which in horizontal cross-section have the form of an elongatedrectangle, and, on the long sides thereof, open and closed sections ofsubstantially equal length alternating with one another.
 9. Bubble trayaccording to claim 6, having caps which in horiZontal cross-section havethe form of a rectangle with not substantially different side lengths,two opposite sides of the rectangle being open and the other two sidesbeing closed.
 10. Bubble tray according to claim 9, characterized inthat the closed portion of the periphery of one cap which is facing anopen peripheral portion of an adjacent cap rises obliquely upwards. 11.Bubble tray according to claim 6, characterized in that the caps are letinto corresponding openings of the tray and thus close off the openingsif they are not lifted by the pressure of an upwardly flowing gas. 12.Bubble tray according to claim 11, characterized in that the caps haveprojections or stops on their upper and lower rims, which limit theirupward and downward movement relatively to the tray.